1. The Field of the Invention
The present invention relates generally to coaxial connectors. More specifically, the present invention relates to a coaxial cable tap having a pair of opposed probes for penetrating into the coaxial cable, and capturing the center conductor of the cable therebetween.
2. The Prior Art
With the increased presence of data processing machines and their peripherals in the modern office environment, the interconnection of these machines with a high speed telecommunications system is a logical requirement for improving their utility. Consequently, the industry has been in need of the development of such an interconnection system.
Most interconnection concepts employ a single coaxial cable as the data transmission medium. Currently available cables, while capable of carrying megabit per second data rates for hundreds or thousands of feet, cannot be easily tapped. Current practice is to cut the cables and interpose a coupling device wherever a tap is needed. This is a costly operation which requires skilled labor and it necessitates temporary interruption of service.
One alternative is to use a tapping device which pierces the jacket of the cable and establishes the electrical contact without actually cutting the electrical conductors. Such a device is disclosed in U.S. Pat. No. 4,120,554, hereby incorporated by reference. As taught thereby, a center conductor is captured between two probes, one of which being spring loaded and the other being stationary. The stationary probe establishes electrical contact, and the spring loaded probe maintains appropriate forces for ensuring the integrity of the connection over time.
The above patented connector envisions that both probes would be sharp enough to pierce the cable unassisted. While the connector probes of the prior art work well, certain shortcomings prevent them from representing an ideal solution of the industry's needs. Since both probes must pierce the cable shield first, and subsequently engage the center conductor, it is imperative that penetration through the shielding be clean. Presently available probes are profiled such that clean penetration of the cable shield cannot be absolutely guaranteed during the termination procedure, and the cable shield may be undesirably deformed inwardly toward the center conductor. Such a deformation increases the possibility that the cable shield and the center conductor will be electrically commoned, resulting in an ineffective cable tap.
By necessity, the probe must be insulated along an axial length between the conductive center conductor engaging tip and the cable shield. Previous probe embodiments, however, comprised a dielectric body surrounding the conductive probe pin having external dimensional irregularities, and sharp dielectric angles, which prevented clean penetration of the cable shield. Worse yet, the dielectric bodies used with current probes provide an external surface which angles sharply from the conductive tip of the probe. The cable shield can catch upon the dielectric body surface angle and be deformed inward during penetration of the cable by the probe. This results in a proximal spacing between the shield and center conductor of the cable which increases the danger of commoning contact.
Accordingly, the industry has been in need of a center conductor engaging probe which is profiled for clean penetration of the shield of the coaxial cable. Still further, the industry has been in need of a profiled dielectric body for such a probe which effectively functions to insulate the tip of the center conductor probe from the cable shield, yet which does not present any external surface irregularities or angles which can inhibit clean penetration of the cable shield.